SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cd2877f49311b3d77fd74bc063f9e87a524818cb87d19b74ed1ba323bde1a1f' 
  AND token = 'CT9bUVGbJbSZeTOye0BbVGOjj/RmPSVKasvEtzDwZ+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}